Question

3. Compare your GC and TLC analysis of the reaction mixture, which method provides more accurate information about the reaction composition?

Answer 1

GC stands for gas chromatography while TLC stands for thin layer chromatography

In GC ,mobile phase is a gas ,whereas in TLC,mobile phase is a liquid.

Practically ,TLC is used often as an analytical tool rather than as a method of purification.TLC is used to quickly determine if a mixture is pure,how many compounds it may contain,and what combination of eluent and stationary phase can be used to separate the components.

However,in gas chromatography,instead of passing a liquid over the stationary phase,an inert phase(helium or nitrogen) moves over the stationary phase.An equilibrium is reached between the compounds absorbed on the stationary phase and compounds moving in the gas phase.

Depending upon the demand of the experiment ,both the methods have their pros and cons.

Advantages of GC over TLC-

1-Higher degree of resolution to resolve components of complex mixture of compounds

2-Higher degree of control over operational parameters such as T programming,gas flow rate e.t.c

3-Higher speed of analysis for optimum resolution

4-Wider choice of sample-ideally suited for analyzing volatile compounds

5-Higher level of sensitivity offering wide range detection.Example-Thermal conductivity,mass selection,flame photometry

6-Easy software optimisation

7-GC columns are easily available

8-Permanent storage of chromatograms are possible

9-GC columns can be reused unlike TLC.